Using the CLI makes it easier to follow and give advice. While I am not advocating feeding your system with commands you do not understand, it is easier to copy and paste a command than clicking around in a GUI that is changing from version to another.

Although new commands are introduced from time to time, the original commands almost always remain the same.

ArchThe arch command is used to print the machine's architecture. For example:

If plain `su` is used then the normal user's environment is maintained so the sbin directories will be missing from PATH (along with a few other differences), only `su -` attains a full root environment.

And just to note that another nice guide to basic command line usage can be read with